THE COMMON SHEEP-SCAB. 71 
tection: Separating with the hand the wool of infested ani- 
mals, the presence of mites will become evident if we find 
round spots upon the skin, which appear whitish where the 
epidermis is a little elevated, and where the lymph forms 
yellowish thin deposits that are easily lifted with the loos- 
ened wool. In somecases the animals show pain if scratched, 
instead of pleasure. The skin of infected animals, if butch- 
ered, show upon their under side red points. The disease 
always starts from small spots, and spreads but very grad- 
ually. Ifneglected, the scabs become thick and of a brown 
color, as if soaked with oil; eventually the skin, entirely de- 
nuded of wool, becomes ankle and between the wrinkles 
cracks appear. If the further increase of the scab-mites is 
not checked the animals become poorer and poorer, and 
die before long. 
By rubbing against posts and other objects many mites 
and their eggs are removed, and thus frequently find lodg- 
ment upon healthy sheep. The mites can readily be found, 
but not in the early stages of the disease. 
REMEDIES.—‘Whatever kills the mite cures the scab” may 
be said to be the rule that we have to follow to exterminate 
them. Internal remedies have no value whatever, except in 
cases where the animal infested is weak, and where rich food 
is necessary to strengthen the patient. 
Creosote, solutions of potash, alkalies mixed with fat, 
oil of turpentine, benzine, kerosene, tar, tobacco, hellebore, 
mercury, and arsenic kill the mites more or less rapidly. 
Vogel made Some experiments, under the microscope, 
and found that scab-mites were killed as follows: 
Within one minute by Stee catbolic soap and ben- 
zine. ; 
Within several minttes by tar and caustic a oats solu- 
tions. 
~ Within one- aabtel to one-half hour by tobacco or helle- 
bore. 
-Within one hour by soft soap. 
Within two hours by arsenic. 
Within four hours by corrosive sublimate. 
In Burope, where all flocks of sheep are given in charge 
